Multimode Multibeam Broadband Terahertz Orbital Angular Momentum Metasurface

In this paper, we propose a linearly polarized terahertz-orbital angular momentum (THz-OAM) electromagnetic (EM) metasurface (MS) capable of simulating the generation of broadband multimode THz-OAM beams within the frequency range 200–240 GHz. Through simulations, processing, and testing of the MS, we demonstrate the generation of OAM EM waves with modes corresponding to l = ±1 and ±2. Furthermore, we demonstrate that the required mode can be adjusted during processing to accommodate specific requirements. The proposed MS exhibits several advantageous characteristics, such as high frequency, large bandwidth, multimode multiplexing, high integration, low cost, and insensitive polarization. These features make it highly valuable for various applications and hold significant importance for the development of the next generation of large-capacity and high-speed communication.